so im changing from tropical fresh water tank that ive had for two years to a 30 gallon saltwater tank.

My questions are: The tap water ive used in the freshwater tank has yet to kill a fish ive not lost one in the two years ive had the tank so would that make it usable for a salt water tank being decholoranted?

also how much rock should i have in it? its dimensions are l 36xw 12xh 17
i really just want clown fish in it.

You may be alright using tap water but RO/DI is really recommended (I know this firsthand ). If you really want to you can try starting off with tap, but just be prepared to do a lot of PWC with RO/DI water down the road if tap isnt working out.

Generally you should aim for at least 1 lb/gal for LR but that's just a guideline. You can get one piece of live rock and the rest base rock - as you guessed correctly, the live rock will seed the rest of the tank with bacteria.

As for cycling, the Articles section has a great writeup. The recommended method is to use a piece of raw shrimp or fish food to generate ammonia, which will then go through the cycle and bacteria will be established. This could take anywhere from a few weeks to over a month.

With clowns you are not limited that much with tankmates. Basically, you could choose almost any nano fish that captivates you. I'll add another post when I have a bit more time with a few suggestions, but off the top of my head, you could get firefish or chromis.

Your LFS may sell RO/DI, or most places that sell RO units and air filters usually sell plain RO water. In the long run, it is better to just buy a RO/DI unit as carting water across town gets old and becomes a hassle after a while. Great post by atte! As for nano fish, go through the nano fish section on www.liveaquaria.com and pick a few out. Most fish in that secition are compatible with each other, but post the list here to make sure everything will go together nicely. Stay away from the dragonet family as they all have a picky feeding habit.

Well i wouldnt need a GPD output being i just own a 30 gallon tank. And what would be the lowest stage you all would recommend? Im just getting a idea of what to look for. Also i heard that you could run your regular tap water through a brita filter then through activated charcoal and then add decholr and it'd be just as good as RO water is this true?

Not true, a Brita/carbon filter removes chemicals and minor things that affect taste of water, while a RO/DI unit gets the total dissolved solids (TDS) as close to 0 as possible which makes the water much better for the tank due to the lack of chlorine, metals, and other products that are added to the water to affect taste, or things that are just naturally there if you are on a well.